linux/drivers/acpi/acpica/exutils.c

// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
 *
 * Module Name: exutils - interpreter/scanner utilities
 *
 * Copyright (C) 2000 - 2022, Intel Corp.
 *
 *****************************************************************************/

/*
 * DEFINE_AML_GLOBALS is tested in amlcode.h
 * to determine whether certain global names should be "defined" or only
 * "declared" in the current compilation. This enhances maintainability
 * by enabling a single header file to embody all knowledge of the names
 * in question.
 *
 * Exactly one module of any executable should #define DEFINE_GLOBALS
 * before #including the header files which use this convention. The
 * names in question will be defined and initialized in that module,
 * and declared as extern in all other modules which #include those
 * header files.
 */

#define DEFINE_AML_GLOBALS

#include <acpi/acpi.h>
#include "accommon.h"
#include "acinterp.h"
#include "amlcode.h"

#define _COMPONENT          ACPI_EXECUTER
ACPI_MODULE_NAME("exutils")

/* Local prototypes */
static u32 acpi_ex_digits_needed(u64 value, u32 base);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_enter_interpreter
 *
 * PARAMETERS:  None
 *
 * RETURN:      None
 *
 * DESCRIPTION: Enter the interpreter execution region. Failure to enter
 *              the interpreter region is a fatal system error. Used in
 *              conjunction with exit_interpreter.
 *
 ******************************************************************************/

void acpi_ex_enter_interpreter(void)
{
	acpi_status status;

	ACPI_FUNCTION_TRACE(ex_enter_interpreter);

	status = acpi_ut_acquire_mutex(ACPI_MTX_INTERPRETER);
	if (ACPI_FAILURE(status)) {
		ACPI_ERROR((AE_INFO,
			    "Could not acquire AML Interpreter mutex"));
	}
	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
	if (ACPI_FAILURE(status)) {
		ACPI_ERROR((AE_INFO, "Could not acquire AML Namespace mutex"));
	}

	return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_exit_interpreter
 *
 * PARAMETERS:  None
 *
 * RETURN:      None
 *
 * DESCRIPTION: Exit the interpreter execution region. This is the top level
 *              routine used to exit the interpreter when all processing has
 *              been completed, or when the method blocks.
 *
 * Cases where the interpreter is unlocked internally:
 *      1) Method will be blocked on a Sleep() AML opcode
 *      2) Method will be blocked on an Acquire() AML opcode
 *      3) Method will be blocked on a Wait() AML opcode
 *      4) Method will be blocked to acquire the global lock
 *      5) Method will be blocked waiting to execute a serialized control
 *          method that is currently executing
 *      6) About to invoke a user-installed opregion handler
 *
 ******************************************************************************/

void acpi_ex_exit_interpreter(void)
{
	acpi_status status;

	ACPI_FUNCTION_TRACE(ex_exit_interpreter);

	status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
	if (ACPI_FAILURE(status)) {
		ACPI_ERROR((AE_INFO, "Could not release AML Namespace mutex"));
	}
	status = acpi_ut_release_mutex(ACPI_MTX_INTERPRETER);
	if (ACPI_FAILURE(status)) {
		ACPI_ERROR((AE_INFO,
			    "Could not release AML Interpreter mutex"));
	}

	return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_truncate_for32bit_table
 *
 * PARAMETERS:  obj_desc        - Object to be truncated
 *
 * RETURN:      TRUE if a truncation was performed, FALSE otherwise.
 *
 * DESCRIPTION: Truncate an ACPI Integer to 32 bits if the execution mode is
 *              32-bit, as determined by the revision of the DSDT.
 *
 ******************************************************************************/

u8 acpi_ex_truncate_for32bit_table(union acpi_operand_object *obj_desc)
{

	ACPI_FUNCTION_ENTRY();

	/*
	 * Object must be a valid number and we must be executing
	 * a control method. Object could be NS node for AML_INT_NAMEPATH_OP.
	 */
	if ((!obj_desc) ||
	    (ACPI_GET_DESCRIPTOR_TYPE(obj_desc) != ACPI_DESC_TYPE_OPERAND) ||
	    (obj_desc->common.type != ACPI_TYPE_INTEGER)) {
		return (FALSE);
	}

	if ((acpi_gbl_integer_byte_width == 4) &&
	    (obj_desc->integer.value > (u64)ACPI_UINT32_MAX)) {
		/*
		 * We are executing in a 32-bit ACPI table. Truncate
		 * the value to 32 bits by zeroing out the upper 32-bit field
		 */
		obj_desc->integer.value &= (u64)ACPI_UINT32_MAX;
		return (TRUE);
	}

	return (FALSE);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_acquire_global_lock
 *
 * PARAMETERS:  field_flags           - Flags with Lock rule:
 *                                      always_lock or never_lock
 *
 * RETURN:      None
 *
 * DESCRIPTION: Obtain the ACPI hardware Global Lock, only if the field
 *              flags specify that it is to be obtained before field access.
 *
 ******************************************************************************/

void acpi_ex_acquire_global_lock(u32 field_flags)
{
	acpi_status status;

	ACPI_FUNCTION_TRACE(ex_acquire_global_lock);

	/* Only use the lock if the always_lock bit is set */

	if (!(field_flags & AML_FIELD_LOCK_RULE_MASK)) {
		return_VOID;
	}

	/* Attempt to get the global lock, wait forever */

	status = acpi_ex_acquire_mutex_object(ACPI_WAIT_FOREVER,
					      acpi_gbl_global_lock_mutex,
					      acpi_os_get_thread_id());

	if (ACPI_FAILURE(status)) {
		ACPI_EXCEPTION((AE_INFO, status,
				"Could not acquire Global Lock"));
	}

	return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_release_global_lock
 *
 * PARAMETERS:  field_flags           - Flags with Lock rule:
 *                                      always_lock or never_lock
 *
 * RETURN:      None
 *
 * DESCRIPTION: Release the ACPI hardware Global Lock
 *
 ******************************************************************************/

void acpi_ex_release_global_lock(u32 field_flags)
{
	acpi_status status;

	ACPI_FUNCTION_TRACE(ex_release_global_lock);

	/* Only use the lock if the always_lock bit is set */

	if (!(field_flags & AML_FIELD_LOCK_RULE_MASK)) {
		return_VOID;
	}

	/* Release the global lock */

	status = acpi_ex_release_mutex_object(acpi_gbl_global_lock_mutex);
	if (ACPI_FAILURE(status)) {

		/* Report the error, but there isn't much else we can do */

		ACPI_EXCEPTION((AE_INFO, status,
				"Could not release Global Lock"));
	}

	return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_digits_needed
 *
 * PARAMETERS:  value           - Value to be represented
 *              base            - Base of representation
 *
 * RETURN:      The number of digits.
 *
 * DESCRIPTION: Calculate the number of digits needed to represent the Value
 *              in the given Base (Radix)
 *
 ******************************************************************************/

static u32 acpi_ex_digits_needed(u64 value, u32 base)
{
	u32 num_digits;
	u64 current_value;

	ACPI_FUNCTION_TRACE(ex_digits_needed);

	/* u64 is unsigned, so we don't worry about a '-' prefix */

	if (value == 0) {
		return_UINT32(1);
	}

	current_value = value;
	num_digits = 0;

	/* Count the digits in the requested base */

	while (current_value) {
		(void)acpi_ut_short_divide(current_value, base, &current_value,
					   NULL);
		num_digits++;
	}

	return_UINT32(num_digits);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_eisa_id_to_string
 *
 * PARAMETERS:  out_string      - Where to put the converted string (8 bytes)
 *              compressed_id   - EISAID to be converted
 *
 * RETURN:      None
 *
 * DESCRIPTION: Convert a numeric EISAID to string representation. Return
 *              buffer must be large enough to hold the string. The string
 *              returned is always exactly of length ACPI_EISAID_STRING_SIZE
 *              (includes null terminator). The EISAID is always 32 bits.
 *
 ******************************************************************************/

void acpi_ex_eisa_id_to_string(char *out_string, u64 compressed_id)
{
	u32 swapped_id;

	ACPI_FUNCTION_ENTRY();

	/* The EISAID should be a 32-bit integer */

	if (compressed_id > ACPI_UINT32_MAX) {
		ACPI_WARNING((AE_INFO,
			      "Expected EISAID is larger than 32 bits: "
			      "0x%8.8X%8.8X, truncating",
			      ACPI_FORMAT_UINT64(compressed_id)));
	}

	/* Swap ID to big-endian to get contiguous bits */

	swapped_id = acpi_ut_dword_byte_swap((u32)compressed_id);

	/* First 3 bytes are uppercase letters. Next 4 bytes are hexadecimal */

	out_string[0] =
	    (char)(0x40 + (((unsigned long)swapped_id >> 26) & 0x1F));
	out_string[1] = (char)(0x40 + ((swapped_id >> 21) & 0x1F));
	out_string[2] = (char)(0x40 + ((swapped_id >> 16) & 0x1F));
	out_string[3] = acpi_ut_hex_to_ascii_char((u64) swapped_id, 12);
	out_string[4] = acpi_ut_hex_to_ascii_char((u64) swapped_id, 8);
	out_string[5] = acpi_ut_hex_to_ascii_char((u64) swapped_id, 4);
	out_string[6] = acpi_ut_hex_to_ascii_char((u64) swapped_id, 0);
	out_string[7] = 0;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_integer_to_string
 *
 * PARAMETERS:  out_string      - Where to put the converted string. At least
 *                                21 bytes are needed to hold the largest
 *                                possible 64-bit integer.
 *              value           - Value to be converted
 *
 * RETURN:      Converted string in out_string
 *
 * DESCRIPTION: Convert a 64-bit integer to decimal string representation.
 *              Assumes string buffer is large enough to hold the string. The
 *              largest string is (ACPI_MAX64_DECIMAL_DIGITS + 1).
 *
 ******************************************************************************/

void acpi_ex_integer_to_string(char *out_string, u64 value)
{
	u32 count;
	u32 digits_needed;
	u32 remainder;

	ACPI_FUNCTION_ENTRY();

	digits_needed = acpi_ex_digits_needed(value, 10);
	out_string[digits_needed] = 0;

	for (count = digits_needed; count > 0; count--) {
		(void)acpi_ut_short_divide(value, 10, &value, &remainder);
		out_string[count - 1] = (char)('0' + remainder);
	}
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_pci_cls_to_string
 *
 * PARAMETERS:  out_string      - Where to put the converted string (7 bytes)
 *              class_code      - PCI class code to be converted (3 bytes)
 *
 * RETURN:      Converted string in out_string
 *
 * DESCRIPTION: Convert 3-bytes PCI class code to string representation.
 *              Return buffer must be large enough to hold the string. The
 *              string returned is always exactly of length
 *              ACPI_PCICLS_STRING_SIZE (includes null terminator).
 *
 ******************************************************************************/

void acpi_ex_pci_cls_to_string(char *out_string, u8 class_code[3])
{

	ACPI_FUNCTION_ENTRY();

	/* All 3 bytes are hexadecimal */

	out_string[0] = acpi_ut_hex_to_ascii_char((u64)class_code[0], 4);
	out_string[1] = acpi_ut_hex_to_ascii_char((u64)class_code[0], 0);
	out_string[2] = acpi_ut_hex_to_ascii_char((u64)class_code[1], 4);
	out_string[3] = acpi_ut_hex_to_ascii_char((u64)class_code[1], 0);
	out_string[4] = acpi_ut_hex_to_ascii_char((u64)class_code[2], 4);
	out_string[5] = acpi_ut_hex_to_ascii_char((u64)class_code[2], 0);
	out_string[6] = 0;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_is_valid_space_id
 *
 * PARAMETERS:  space_id            - ID to be validated
 *
 * RETURN:      TRUE if space_id is a valid/supported ID.
 *
 * DESCRIPTION: Validate an operation region space_ID.
 *
 ******************************************************************************/

u8 acpi_is_valid_space_id(u8 space_id)
{

	if ((space_id >= ACPI_NUM_PREDEFINED_REGIONS) &&
	    (space_id < ACPI_USER_REGION_BEGIN) &&
	    (space_id != ACPI_ADR_SPACE_DATA_TABLE) &&
	    (space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)) {
		return (FALSE);
	}

	return (TRUE);
}